<template>
  <div class="xtx-carousel" @mouseenter="stop()" @mouseleave="start()">
      <!-- 图片 -->
    <ul class="carousel-body">
      <li class="carousel-item" v-for="(item,i) in sliders" :key="item.id" :class="{fade:activeIndex===i}">
        <RouterLink v-if="item.hrefUrl" :to="item.hrefUrl">
          <img
            :src="item.imgUrl"
            alt=""
          />
        </RouterLink>
        <div v-else class="slider">
          <RouterLink v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
            <img :src="goods.picture" alt="">
            <p class="name ellipsis">{{goods.name}}</p>
            <p class="price">&yen;{{goods.price}}</p>
          </RouterLink>
        </div>
      </li>
    </ul>
      <!-- 按钮 -->
    <a href="javascript:;" class="carousel-btn prev" @click="toggle(-1)">
      <i class="iconfont icon-angle-left"></i>
    </a>
    <a href="javascript:;" class="carousel-btn next" @click="toggle(1)">
      <i class="iconfont icon-angle-right"></i>
    </a>
      <!-- 下方小按钮 -->
    <div class="carousel-indicator">
      <span :class="{active:activeIndex===index}" v-for="(i,index) in sliders" :key="i.id" @click="activeIndex = index"></span>
    </div>
  </div>
</template>

<script>
import { ref, watch, onUnmounted } from 'vue'
export default {
  name: 'XtxCarousel',
  props: {
    sliders: {
      type: Array,
      default: () => [] // 返回一个新创建的新对象 防止复用时 内存地址一样
    },
    duration: {
      type: Number,
      default: 3000
    },
    autoPlay: {
      type: Boolean,
      default: false
    }
  },
  setup (props) {
    const activeIndex = ref(0)
    // 上一张，下一张
    const toggle = (step) => {
      const temp = activeIndex.value + step
      if (temp < 0) {
        activeIndex.value = props.sliders.length - 1
        return
      }
      if (temp > props.sliders.length - 1) {
        activeIndex.value = 0
        return
      }
      activeIndex.value = temp
    }
    // 自动轮播实现
    let timer = null
    const autoFn = () => {
      clearInterval(timer)
      timer = setInterval(() => {
        toggle(1)
      }, props.duration)
    }
    watch(() => props.sliders, (newVal) => {
      if (newVal.length > 1 && props.autoPlay) {
        autoFn()
      }
    }, {
      immediate: true
    })
    // 销毁组件，清理定时器
    onUnmounted(() => {
      clearInterval(timer)
    })
    // 如果有自动播放，鼠标进入离开，暂停，开启
    const stop = () => {
      if (timer) clearInterval(timer)
    }
    const start = () => {
      if (props.sliders.length > 1 && props.autoPlay) {
        autoFn()
      }
    }
    return { activeIndex, toggle, stop, start }
  }
}
</script>

<style scoped lang="less">
// 商品详情轮播商品
.slider {
  display: flex;
  justify-content: space-around;
  padding: 0 40px;
  > a {
    width: 240px;
    text-align: center;
    img {
      padding: 20px;
      width: 230px!important;
      height: 230px!important;
    }
    .name {
      font-size: 16px;
      color: #666;
      padding: 0 40px;
    }
    .price {
      font-size: 16px;
      color: @priceColor;
      margin-top: 15px;
    }
  }
}
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>
